/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/MeshGeodesicSurfaceTracer.h
The PrimaryEdge will be aligned with the x-axis in 2d ( and must be one of the edges of the triangle indicated by TriID)
FTangentTri2 ( const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) & Mesh, int32 TriID, int32 PrimaryEdgeID )